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Karaca I, Aldemir Dikici B. Quantitative Evaluation of the Pore and Window Sizes of Tissue Engineering Scaffolds on Scanning Electron Microscope Images Using Deep Learning. ACS OMEGA 2024; 9:24695-24706. [PMID: 38882138 PMCID: PMC11170757 DOI: 10.1021/acsomega.4c01234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 04/24/2024] [Accepted: 04/29/2024] [Indexed: 06/18/2024]
Abstract
The morphological characteristics of tissue engineering scaffolds, such as pore and window diameters, are crucial, as they directly impact cell-material interactions, attachment, spreading, infiltration of the cells, degradation rate and the mechanical properties of the scaffolds. Scanning electron microscopy (SEM) is one of the most commonly used techniques for characterizing the microarchitecture of tissue engineering scaffolds due to its advantages, such as being easily accessible and having a short examination time. However, SEM images provide qualitative data that need to be manually measured using software such as ImageJ to quantify the morphological features of the scaffolds. As it is not practical to measure each pore/window in the SEM images as it requires extensive time and effort, only the number of pores/windows is measured and assumed to represent the whole sample, which may cause user bias. Additionally, depending on the number of samples and groups, a study may require measuring thousands of samples and the human error rate may increase. To overcome such problems, in this study, a deep learning model (Pore D2) was developed to quantify the morphological features (such as the pore size and window size) of the open-porous scaffolds automatically for the first time. The developed algorithm was tested on emulsion-templated scaffolds fabricated under different fabrication conditions, such as changing mixing speed, temperature, and surfactant concentration, which resulted in scaffolds with various morphologies. Along with the developed model, blind manual measurements were taken, and the results showed that the developed tool is capable of quantifying pore and window sizes with a high accuracy. Quantifying the morphological features of scaffolds fabricated under different circumstances and controlling these features enable us to engineer tissue engineering scaffolds precisely for specific applications. Pore D2, an open-source software, is available for everyone at the following link: https://github.com/ilaydakaraca/PoreD2.
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Affiliation(s)
- Ilayda Karaca
- Department of Bioengineering, Izmir Institute of Technology, Urla, Izmir 35433, Turkey
| | - Betül Aldemir Dikici
- Department of Bioengineering, Izmir Institute of Technology, Urla, Izmir 35433, Turkey
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2
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Touchet TJ, Horelica M, Gruenbaum R, Lewy K, Hines E, Stranahan L, Saunders WB, Maitland DJ. Fabrication and In Vivo Assessment of Oxidatively Responsive PolyHIPE Scaffolds for Use in Diabetic Orthopedic Applications. Macromol Biosci 2024; 24:e2300393. [PMID: 37904644 DOI: 10.1002/mabi.202300393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 10/16/2023] [Indexed: 11/01/2023]
Abstract
Achieving surgical success in orthopedic patients with metabolic disease remains a substantial challenge. Diabetic patients exhibit a unique tissue microenvironment consisting of high levels of reactive oxygen species (ROS), which promotes osteoclastic activity and leads to decreased bone healing. Alternative solutions, such as synthetic grafts, incorporating progenitor cells or growth factors, can be costly and have processing constraints. Previously, the potential for thiol-methacrylate networks to sequester ROS while possessing tunable mechanical properties and degradation rates has been demonstrated. In this study, the ability to fabricate thiol-methacrylate interconnected porous scaffolds using emulsion templating to create monoliths with an average porosity of 97.0% is reported. The average pore sizes of the scaffolds range from 27 to 656 µm. The scaffolds can sequester pathologic levels of ROS via hydrogen peroxide consumption and are not impacted by sterilization. Subcutaneous implantation shows no signs of acute toxicity. Finally, in a 6-week bilateral calvarial defect model in Zucker diabetic fatty rats, ROS scaffolds increase new bone volume by 66% over sham defects. Histologic analysis identifies woven bone infiltration throughout the scaffold and neovascularization. Overall, this study suggests that porous thiol-methacrylate scaffolds may improve healing for bone grafting applications where high levels of ROS hinder bone growth.
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Affiliation(s)
- Tyler J Touchet
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
- Enovis, 727 N. Shepherd Drive Suite 100, Houston, TX, 77007, USA
| | - Madeleine Horelica
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Rachel Gruenbaum
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Keith Lewy
- Department of Comparative Medicine, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Elizabeth Hines
- Department of Veterinary Pathobiology, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Lauren Stranahan
- Department of Veterinary Pathobiology, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - W Brian Saunders
- Department of Small Animal Clinical Sciences, School of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Duncan J Maitland
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
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Ozkendir O, Karaca I, Cullu S, Erdoğan OC, Yaşar HN, Dikici S, Owen R, Aldemir Dikici B. Engineering periodontal tissue interfaces using multiphasic scaffolds and membranes for guided bone and tissue regeneration. BIOMATERIALS ADVANCES 2024; 157:213732. [PMID: 38134730 DOI: 10.1016/j.bioadv.2023.213732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 12/06/2023] [Accepted: 12/11/2023] [Indexed: 12/24/2023]
Abstract
Periodontal diseases are one of the greatest healthcare burdens worldwide. The periodontal tissue compartment is an anatomical tissue interface formed from the periodontal ligament, gingiva, cementum, and bone. This multifaceted composition makes tissue engineering strategies challenging to develop due to the interface of hard and soft tissues requiring multiphase scaffolds to recreate the native tissue architecture. Multilayer constructs can better mimic tissue interfaces due to the individually tuneable layers. They have different characteristics in each layer, with modulation of mechanical properties, material type, porosity, pore size, morphology, degradation properties, and drug-releasing profile all possible. The greatest challenge of multilayer constructs is to mechanically integrate consecutive layers to avoid delamination, especially when using multiple manufacturing processes. Here, we review the development of multilayer scaffolds that aim to recapitulate native periodontal tissue interfaces in terms of physical, chemical, and biological characteristics. Important properties of multiphasic biodegradable scaffolds are highlighted and summarised, with design requirements, biomaterials, and fabrication methods, as well as post-treatment and drug/growth factor incorporation discussed.
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Affiliation(s)
- Ozgu Ozkendir
- Department of Bioengineering, Izmir Institute of Technology, Urla, Izmir 35433, Turkey
| | - Ilayda Karaca
- Department of Bioengineering, Izmir Institute of Technology, Urla, Izmir 35433, Turkey
| | - Selin Cullu
- Department of Bioengineering, Izmir Institute of Technology, Urla, Izmir 35433, Turkey
| | - Oğul Can Erdoğan
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, Urla, Izmir 35433, Turkey
| | - Hüsniye Nur Yaşar
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, Urla, Izmir 35433, Turkey
| | - Serkan Dikici
- Department of Bioengineering, Izmir Institute of Technology, Urla, Izmir 35433, Turkey
| | - Robert Owen
- School of Pharmacy, University of Nottingham Biodiscovery Institute, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Betül Aldemir Dikici
- Department of Bioengineering, Izmir Institute of Technology, Urla, Izmir 35433, Turkey.
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McKenzie TJ, Brunet T, Kissell LN, Strobbia P, Ayres N. Polydimethylsiloxane Polymerized Emulsions for Acoustic Materials Prepared Using Reactive Triblock Copolymer Surfactants. ACS APPLIED MATERIALS & INTERFACES 2023; 15:58917-58930. [PMID: 38063480 DOI: 10.1021/acsami.3c14859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
Porous polymers have interesting acoustic properties including wave dampening and acoustic impedance matching and may be used in numerous acoustic applications, e.g., waveguiding or acoustic cloaking. These materials can be prepared by the inclusion of gas-filled voids, or pores, within an elastic polymer network; therefore, porous polymers that have controlled porosity values and a wide range of possible mechanical properties are needed, as these are key factors that impact the sound-dampening properties. Here, the synthesis of acoustic materials with varying porosities and mechanical properties that could be controlled independent of the pore morphology using emulsion-templated polymerizations is described. Polydimethylsiloxane-based ABA triblock copolymer surfactants were prepared using reversible addition-fragmentation chain transfer polymerizations to control the emulsion template and act as an additional cross-linker in the polymerization. Acoustic materials prepared with reactive surfactants possessed a storage modulus of ∼300 kPa at a total porosity of 71% compared to materials prepared using analogous nonreactive surfactants that possessed storage modulus values of ∼150 kPa at similar porosities. These materials display very low longitudinal sound speeds of ∼35 m/s at ultrasonic frequencies, making them excellent candidates in the preparation of acoustic devices such as metasurfaces or lenses.
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Affiliation(s)
- Tucker J McKenzie
- Department of Chemistry, The University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221, United States
| | - Thomas Brunet
- Institut de Mécanique et d'Ingénierie, University of Bordeaux─CNRS─Bordeaux INP, Talence 33405, France
| | - Lyndsay N Kissell
- Department of Chemistry, University of Cincinnati, 201 Crosley Tower, 301 Clifton Ct, Cincinnati, Ohio 45221, United States
| | - Pietro Strobbia
- Department of Chemistry, University of Cincinnati, 201 Crosley Tower, 301 Clifton Ct, Cincinnati, Ohio 45221, United States
| | - Neil Ayres
- Department of Chemistry, The University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221, United States
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Furmidge R, Jackson CE, Velázquez de la Paz MF, Workman VL, Green NH, Reilly GC, Hearnden V, Claeyssens F. Surfactant-free gelatin-stabilised biodegradable polymerised high internal phase emulsions with macroporous structures. Front Chem 2023; 11:1236944. [PMID: 37681209 PMCID: PMC10481965 DOI: 10.3389/fchem.2023.1236944] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 08/10/2023] [Indexed: 09/09/2023] Open
Abstract
High internal phase emulsion (HIPE) templating is a well-established method for the generation of polymeric materials with high porosity (>74%) and degree of interconnectivity. The porosity and pore size can be altered by adjusting parameters during emulsification, which affects the properties of the resulting porous structure. However, there remain challenges for the fabrication of polyHIPEs, including typically small pore sizes (∼20-50 μm) and the use of surfactants, which can limit their use in biological applications. Here, we present the use of gelatin, a natural polymer, during the formation of polyHIPE structures, through the use of two biodegradable polymers, polycaprolactone-methacrylate (PCL-M) and polyglycerol sebacate-methacrylate (PGS-M). When gelatin is used as the internal phase, it is capable of stabilising emulsions without the need for an additional surfactant. Furthermore, by changing the concentration of gelatin within the internal phase, the pore size of the resulting polyHIPE can be tuned. 5% gelatin solution resulted in the largest mean pore size, increasing from 53 μm to 80 μm and 28 μm to 94 µm for PCL-M and PGS-M respectively. In addition, the inclusion of gelatin further increased the mechanical properties of the polyHIPEs and increased the period an emulsion could be stored before polymerisation. Our results demonstrate the potential to use gelatin for the fabrication of surfactant-free polyHIPEs with macroporous structures, with potential applications in tissue engineering, environmental and agricultural industries.
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Affiliation(s)
- Rachel Furmidge
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
| | - Caitlin E. Jackson
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
| | - María Fernanda Velázquez de la Paz
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
| | - Victoria L. Workman
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
| | - Nicola H. Green
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
| | - Gwendolen C. Reilly
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
| | - Vanessa Hearnden
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
| | - Frederik Claeyssens
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
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Hierarchical Macroporous PolyDCPD Composites from Surface-Modified Calcite-Stabilized High Internal Phase Emulsions. Polymers (Basel) 2023; 15:polym15010228. [PMID: 36616580 PMCID: PMC9824432 DOI: 10.3390/polym15010228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 11/25/2022] [Accepted: 11/28/2022] [Indexed: 01/03/2023] Open
Abstract
High Internal Phase Emulsions (HIPEs) of dicyclopentadiene (DCPD) were prepared using mixtures of surface-modified calcite (mCalcite) and a non-ionic surfactant. Twelve different emulsion formulations were created using an experimental design methodology. Three distinctive levels of the internal phase ratio, the amount of mCalcite loading, and the surfactant were used to prepare the HIPEs. Accordingly, macroporous polyDCPD composites were synthesized by performing ring-opening metathesis polymerization (ROMP) on the HIPEs. The variations in the morphological and physical properties of the composites were investigated in terms of experimental parameters. In the end, five different model equations were derived with a confidence level of 95%. The main and binary interaction effects of the experimental parameters on the responses, such as the average cavity size, interconnecting pore size, specific surface area, foam density, and compression modulus, were demonstrated. The synergistic interaction between the amount of surfactant, the amount of mCalcite loading, and the internal phase ratio appeared to have a dominant role in the average cavity diameter. The solo effect of the internal phase ratio on the interconnecting pore size, foam density, and compression modulus was confirmed. In addition, it was demonstrated that the specific surface area of the composites was mainly changed depending on the amount of mCalcite loading.
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Synergistic effect of type and concentration of surfactant and diluting solvent on the morphology of emulsion templated matrices developed as tissue engineering scaffolds. REACT FUNCT POLYM 2022. [DOI: 10.1016/j.reactfunctpolym.2022.105387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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